Plaque Characterization by Coronary Computed Tomography Angiography and the Likelihood of Acute Coronary Events in Mid-Term Follow-Up.

BACKGROUND: Coronary computed tomography angiography (CTA)-verified positive remodeling and low attenuation plaques are considered morphological characteristics of high-risk plaque (HRP) and predict short-term risk of acute coronary syndrome (ACS). OBJECTIVES: This study evaluated whether plaque characteristics by CTA predict mid-term likelihood of ACS. METHODS: The presence of HRP and significant stenosis (SS) of ≥70% were evaluated in 3,158 patients undergoing CTA. Serial CTA was performed in 449 patients, and plaque progression (PP) was evaluated. Outcomes (fatal and nonfatal ACS) were recorded during follow-up (mean 3.9 ± 2.4 years). RESULTS: ACS occurred in 88 (2.8%) patients: 48 (16.3%) of 294 HRP(+) and 40 (1.4%) of 2,864 HRP(-) patients. ACS was also significantly more frequent in SS(+) (36 of 659; 5.5%) than SS(-) patients (52 of 2,499; 2.1%). HRP(+)/SS(+) (19%) and HRP(+)/SS(-) (15%) had higher rates of ACS compared with no-plaque patients (0.6%). Although ACS incidence was relatively low in HRP(-) patients, the cumulative number of patients with ACS developing from HRP(-) lesions (n = 43) was similar to ACS patients with HRP(+) lesions (n = 45). In patients with serial CTA, PP also was an independent predictor of ACS, with HRP (27%; p < 0.0001) and without HRP (10%) compared with HRP(-)/PP(-) patients (0.3%). CONCLUSIONS: CTA-verified HRP was an independent predictor of ACS. However, the cumulative number of ACS patients with HRP(-) was similar to patients with HRP(+). Additionally, plaque progression detected by serial CTA was an independent predictor of ACS.

Major bleeding complications related to combined antithrombotic therapy in atrial fibrillation patients 12 months after coronary artery stenting.

BACKGROUND AND PURPOSE: Many patients with atrial fibrillation (AF) and coronary artery stent deployment are given both antiplatelet drug and warfarin. Little information is available as to the relationship between the antithrombotic therapies in the late phase after stenting and the clinical outcomes of these patients. We examined the clinical outcomes of AF patients 12 months after coronary artery stenting. METHODS: We retrospectively examined 146 patients and classified them into three groups according to the antithrombotic therapies [dual antiplatelet therapy (DAPT), single antiplatelet therapy (SAPT) plus warfarin, and DAPT plus warfarin] 12 months after stenting. We defined the primary endpoint as Thrombolysis in Myocardial Infarction major bleeding and the secondary endpoint as a composite of adverse events (CAE: all-cause death, nonfatal myocardial infarction, intracranial bleeding, and cerebral infarction). RESULTS: During a median follow-up of 37 months, major bleeding and CAE were observed in 14 (9.6%) and 46 (31.5%) patients, respectively. DAPT plus warfarin was an independent risk factor for major bleeding in a multivariate Cox hazard regression model after adjustment for age, gender, and the type of AF (hazard ratio: 4.20; 95% confidence interval: 1.13-17.27; p=0.033). No significant clinical variables were found for CAE. CONCLUSIONS: Prolonged use of DAPT with warfarin significantly increases the risk of major bleeding in AF patients after coronary artery stenting. Individualized antithrombotic treatment is required in these patients to prevent major bleeding.

Adding coronary computed tomography angiography to invasive coronary angiography improves prediction of cardiac events.

BACKGROUND: The additive value of plaque characteristics determined by computed tomography angiography (CTA) in patients undergoing invasive coronary angiography (ICA) has not been established. METHODS AND RESULTS: We studied 676 patients undergoing ICA and CTA within 3 months. The luminal diameter narrowing based on ICA and the presence of high risk plaque (HRP) based on CTA were assessed in all coronary artery segments except for those after or before scheduled treatment. We followed their cardiac events including cardiac death, acute coronary syndrome (ACS), and revascularization for de novo lesions ≥3 months after ICA. The incidence of coronary events was higher in the segments including >25% luminal narrowing than in those without (2.94% vs. 0.31%, P<0.0001), and higher in the segments containing HRP than in those without (12.6 vs. 0.46%, P<0.0001). Greater than 25% residual luminal narrowing and the presence of HRP were identified as independent predictors of cardiac events after risk adjustment for age, gender, and history of ACS (hazard ratio [HR], 3.22; 95% confidence interval [CI]: 1.29-10.76; P=0.0092, HR, 2.64; 95% CI: 1.59-4.35; P=0.0002, respectively). Adding the presence of HRP to a model including age, gender, ACS history, and >25% residual stenosis improved the prediction of cardiac events. CONCLUSIONS: Assessment of coronary plaque characteristics on CTA improves the prediction of cardiac events in patients undergoing ICA.

Characteristics of plaque progression detected by serial coronary computed tomography angiography.

We previously reported that serial coronary computed tomography angiography (CTA) had a potential to evaluate the interval change of plaque morphology of coronary arteries. The aim of this study was to evaluate variables associated with the plaque progression by serial CTA. We included 148 patients (age 66.3 ± 9.8 years, male 81.1 %, median scan interval 12 months) with coronary artery disease undergoing serial CTA. Each coronary artery was compared visually between baseline and follow-up CTA to detect plaque progression. Baseline characteristics between progression and nonprogression patients did not demonstrate any significant differences. Logistic analysis revealed that only low-density lipoprotein cholesterol (LDL-C) ≥100 mg/dl at follow-up was associated with plaque progression (odds ratio 2.59, 95 % confidence interval 1.12-6.34, P = 0.0263). Cutoff value of LDL-C for plaque progression at follow-up was 103.0 mg/dl based on receiver-operator characteristic curves analyses. Of the 36 progressive lesions in 32 patients, plaque composition at baseline included 13 lesions (36.1 %) of noncalcified plaque, 1 lesion (2.8 %) of calcified plaque, 12 lesions (33.3 %) of partially calcified plaque, and the remaining 10 lesions (27.8 %) had no plaque at baseline and revealed de novo plaques at follow-up. There were 9 lesions (25 %) with high-risk plaque (HRP) characteristics at baseline and 18 lesions (50 %) with HRP at follow-up. Plaque progression of coronary arteries by serial CTA was associated with LDL-C ≥100 mg/dl at follow-up regardless of baseline LDL-C level. There was no specific finding to predict plaque progression on the baseline plaque characteristics.

A combination of anatomical and functional evaluations improves the prediction of cardiac event in patients with coronary artery bypass.

OBJECTIVE: To study the usefulness of combined risk stratification of coronary CT angiography (CTA) and myocardial perfusion imaging (MPI) in patients with previous coronary-artery-bypass grafting (CABG). DESIGN: A retrospective, observational, single centre study. SETTING AND PATIENTS: 204 patients (84.3% men, mean age 68.7±7.6) undergoing CTA and MPI. MAIN OUTCOME MEASURES: CTA defined unprotected coronary territories (UCT; 0, 1, 2 or 3) by evaluating the number of significant stenoses which were defined as the left main trunk ≥50% diameter stenosis, other native vessel stenosis ≥70% or graft stenosis ≥70%. Using a cut-off value with receiver-operating characteristics analysis, all patients were divided into four groups: group A (UCT=0, summed stress score (SSS)<4), group B (UCT≥1, SSS<4), group C (UCT=0, SSS≥4) and group D (UCT≥1, SSS≥4). RESULTS: Cardiac events, as a composite end point including cardiac death, non-fatal myocardial infarction, unstable angina requiring revascularisation and heart-failure hospitalisation, were observed in 27 patients for a median follow-up of 27.5 months. The annual event rates were 1.1%, 2%, 5.7% and 12.9% of patients in groups A, B, C and D, respectively (log rank p value <0.0001). Adding UCT or SSS to a model with significant clinical factors including left ventricular ejection fraction, time since CABG and Euro SCORE II improved the prediction of events, while adding UCT and SSS to the model improved it greatly with increasing C-index, net reclassification improvement and integrated discrimination improvement. CONCLUSIONS: The combination of anatomical and functional evaluations non-invasively enhances the predictive accuracy of cardiac events in patients with CABG.

Morphologic and functional assessment of coronary artery disease--potential application of computed tomography angiography and myocardial perfusion imaging.

BACKGROUND: The role of combined evaluation of myocardial perfusion imaging (MPI; by single-photon emission computed tomography) and computed tomography angiography (CTA) for risk stratification of coronary artery disease was evaluated. For CTA, the extent of luminal stenosis, and also the features of high-risk plaques (HRP, including positive remodeling and low attenuation) were evaluated. METHODS AND RESULTS: A total of 304 patients (65 ± 11 years, male 72%, median follow-up: 24 months) who underwent CTA and MPI were enrolled in the study. Summed stress scores and summed difference scores (SDS) for MPI, stenosis, and HRP were evaluated, and event rates were compared. Cardiac events were defined as acute coronary event including cardiac death or non-fatal acute myocardial infarction, and unstable angina requiring revascularization. Of 304 patients, 51 (16.8%) underwent early revascularization. In the remaining 253 patients, an event occurred in 11 (4.3%). HRP (hazard ratio [HR], 4.75, P=0.00171) and stenosis (+) with SDS >0 (HR, 4.58, P=0.0461) were significant independent predictors of cardiac event. The event rate for stenosis (+) with SDS >0 was significantly higher than others (log-rank P=0.0490). The event rates were significantly different between HRP(+) and HRP(-) (16.1% vs. 2.7%, log-rank P=0.0013). CONCLUSIONS: HRP on CTA was an independent predictor of acute coronary events, as was stenosis (+) with SDS >0, and HRP had increased prognostic value over stenosis and abnormal MPI findings.

Role of ¹²³I-BMIPP and serum B-type natriuretic peptide for the evaluation of patients with heart failure.

INTRODUCTION: Myocardial scintigraphy with ¹²³I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (¹²³I-BMIPP) is used to evaluate impaired fatty acid metabolism. B-type natriuretic peptide (BNP), which is secreted by the ventricular myocardium on stretching and/or pressure overload, is a useful cardiac biomarker. This study aimed to evaluate the usefulness of ¹²³I-BMIPP imaging and serum BNP levels in patients with heart failure (HF). METHODS: 113 patients with HF were enrolled. There were 68 patients with ischaemic heart disease (IHD) and 22 with overt HF. Cardiac scintigraphy was performed 7 ± 3 days after admission, and heart-to-mediastinum (H/M) count ratios on early and delayed images and washout rates (WR) of ¹²³I-BMIPP were recorded. Serum BNP levels were recorded on the day of ¹²³I-BMIPP imaging. The ejection fraction (EF) was calculated just before cardiac scintigraphy using conventional echocardiography. RESULTS: The mean BNP level and EF were 282 pg/mL and 47%, respectively, with significant correlation between them. The mean H/M count ratios on early and delayed images were 2.29 and 1.93, respectively, showing significant positive correlations with EF (r = 0.31, p = 0.0006). The WR was significantly correlated with EF (r = -0.36, p < 0.0001) and BNP levels (r = 0.33, p = 0.003), and mean WR was significantly higher in patients with overt HF compared to those without (p < 0.001). Patients with IHD had significantly higher EFs than those with non-IHD (p = 0.03). CONCLUSION: The evaluation of impaired myocardial metabolism using ¹²³I-BMIPP scintigraphy and serum BNP levels appears to be useful for the evaluation of severity of HF.

Association between clinical outcome and antiarrhythmic treatment in heart failure patients who have atrial fibrillation upon admission to the hospital.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) are associated with significant mortality and morbidity. We sometimes encounter patients who have AF upon admission to the hospital, but it spontaneously converts to sinus rhythm within several days (i.e. converter). PURPOSE: We examined the association between the outcome and types of strategy for AF treatment in converters. METHODS: From January 2000 to December 2005, we identified 95 converters (age 69 ± 12 years) presenting with worsening HF and AF upon admission, in which sinus rhythm was restored within 7 days without either electrical or pharmacological cardioversion. The patients were classified into three groups according to the antiarrhythmic drug (AAD) therapy used: class I AAD, class III AAD, and rate-control drug. The patients were followed for 36 ± 23 months. RESULTS: The left ventricular ejection fraction (LVEF) significantly improved with conversion to sinus rhythm (38 ± 14% vs. 47 ± 13%, p<0.05). Those receiving class I AAD had a trend toward a well-preserved LVEF (50 ± 13%, n=35) as compared to those receiving class III AAD (43 ± 12%, n=24) or rate-control drug (47 ± 14%, n=36). In the patients receiving class I AAD, the rate of all-cause death increased 1.9-fold (p=0.009) compared to those receiving class III AAD, and 1.7-fold (p=0.010) compared to those taking rate-control drug. A hospitalization for HF was observed in 49 (52%) patients, however there was no significant difference in the rate of hospitalization among the three groups (p=0.890). Those receiving rate-control drugs had a 50% lower rate of the development of persistent AF than those taking class III AAD (p=0.019). CONCLUSIONS: A rate-control strategy should be the primary approach for converters to reduce mortality and development of persistent AF.

Coronary plaque characteristics in patients with mild chronic kidney disease. Analysis by 320-row area detector computed tomography.

BACKGROUND: The differences in the coronary plaque characteristics between patients with mild chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] 30-59 ml·min(-1) · 1.73 m(-2)) and those without CKD (eGFR ≥60) by 320-row area detector computed tomography (CT) have not been studied. METHODS AND RESULTS: We enrolled 487 patients undergoing coronary CT angiography with suspected stable coronary artery disease (mean age: 66.6±10.8 years, 131 with mild CKD) and analyzed 6,352 segments. All coronary plaques were characterized for the presence of vessel remodeling, plaque consistency and the disposition of coronary calcification, and a plaque with positive vessel remodeling and/or low-attenuation was defined as high risk. The number of diseased segments per patient was higher in mild CKD patients than in those without CKD (4.61±3.83 vs. 2.95±3.11, P<0.0001). The prevalence of severe stenosis (≥70% luminal diameter) was significantly higher in cases of mild CKD than in no CKD (35.1% vs. 19.4%, P=0.0003), but there was no significant difference in the prevalence of high-risk plaque (13.0% vs. 9.8%, P=0.3189). CONCLUSIONS: The severity of coronary artery stenosis was higher in the patients with mild CKD, though there was no significant difference in the prevalence of high-risk plaque. We suggest that the high risk of coronary events in patients with CKD is related to the severity of stenosis rather than to the characteristics of plaque.

Beat-to-beat variability of T-wave amplitude for the risk assessment of ventricular tachyarrhythmia in patients without structural heart disease.

AIMS: Increased temporal repolarization lability, assessed by beat-to-beat variability of T-wave amplitude (TAV), has been shown to be associated with ventricular tachyarrhythmia in patients with a variety of clinical conditions. The aim of this study was to test the ability of TAV to identify patients presenting with malignant ventricular arrhythmia and to predict subsequent occurrences. METHODS AND RESULTS: We studied 20 consecutive patients (age 42 ± 15 years, mean ± standard deviation) presenting with ventricular tachyarrhythmia who did not have substantial underlying heart disease and compared them with 40 age- and sex-matched control subjects. The TAV was determined by Holter recording (Ela Medical). Patients with ventricular tachyarrhythmia had a higher maximum value of TAV (max TAV: 38 ± 18 vs. 22 ± 15 µV, P < 0.001) than did the controls. The sensitivity and specificity of max TAV > 22.4 µV for detecting the occurrence of ventricular tachyarrhythmia were 77 and 90%, respectively. During a mean follow-up period of 23 months, three patients had relapses of ventricular tachyarrhythmia. Patients with a recurrence of ventricular tachyarrhythmia had a trend towards a higher max TAV as compared with those who had ventricular tachyarrhythmia but did not relapse (56 ± 23 vs. 36 ± 16 µV, P = 0.061). CONCLUSION: Our results suggest that Holter-derived TAV might be associated with the occurrence and recurrence of ventricular tachyarrhythmia in patients without structural heart disease. Prospective validation will be necessary to assess the potential diagnostic value of the TAV in a large general population.

Prediction of the no-reflow phenomenon during percutaneous coronary intervention using coronary computed tomography angiography.

Coronary computed tomography angiography (CTA) can assess plaque characteristics and plaque size noninvasively. The purpose of this study was to investigate whether coronary CTA before percutaneous coronary intervention (PCI) can predict the no-reflow phenomenon during PCI. Seventy-eight patients [acute coronary syndrome (ACS) = 43, stable angina pectoris (SAP) = 35, male/female = 72/6, age: 65 ± 10 years] who underwent 16- or 64-slice CTA in the 4 weeks before PCI were enrolled. The low attenuation plaque size on CTA was compared between patients with (NR+) and without the no-reflow phenomenon (NR-). No-reflow phenomenon was observed in 11 patients, including 10 patients with ACS and 1 patient with SAP. Low attenuation plaque was detected in 9 (82%) NR(+) lesions and 35 (52%) NR(-) lesions. The length of low attenuation plaque was significantly longer in NR(+) than in NR(-) patients (9.0 ± 6.5 vs. 1.6 ± 2.7 mm, p < 0.0001). On step-wise regression analysis, ACS (p = 0.036, 95% CI = 0.009-0.258) and the presence of low attenuation plaque with a length >4.7 mm (p < 0.001, 95% CI = 0.447-0.778) were significant independent predictors of NR(-) no-reflow phenomenon. Low attenuation plaque with lesion length of >4.7 mm on coronary CTA and ACS were the significant predictors for the no-reflow phenomenon during PCI. Coronary CTA assessment before PCI would be useful to predict coronary events during PCI in advance.

Serial coronary CT angiography-verified changes in plaque characteristics as an end point: evaluation of effect of statin intervention.

OBJECTIVES: This study sought to assess, by serial computed tomography angiography (CTA), the effect of statin treatment on coronary plaque morphology. BACKGROUND: In addition to the assessment of luminal stenosis, CTA also allows characterization of plaque morphology. Large, positively remodeled plaques with large necrotic cores have been reported as indicators of plaque instability. METHODS: CTA was performed in 32 patients (26 men, ages 64.3 +/- 8.5 years). Of these, 24 received fluvastatin after the baseline study; 8 subjects who refused statin treatment were followed as the control subjects. Serial imaging was performed after a median interval of 12 months. All vessels were examined in every subject, and a 10-mm-long segment was identified for comparison before and after intervention. Total plaque volume, low attenuation plaque (LAP) volume, lumen volume, and remodeling index were calculated. RESULTS: In the statin-treated patients, the total plaque volume (92.3 +/- 37.7 vs. 76.4 +/- 26.5 mm(3), p < 0.01) and LAP volume (4.9 +/- 7.8 vs. 1.3 +/- 2.3 mm(3), p = 0.01) were significantly reduced over time; however, there was no change in the lumen volume (63.9 +/- 25.3 vs. 65.2 +/- 26.2 mm(3), p = 0.59). On the other hand, no change was observed in the CTA characteristics in the control subjects, including total plaque volume (94.4 +/- 21.2 vs. 98.4 +/- 28.6 mm(3), p = 0.48), LAP volume (2.1 +/- 3.0 vs. 2.3 +/- 3.6 mm(3), p = 0.91), and lumen volume (80.5 +/- 20.7 vs. 75.0 +/- 16.3 mm(3), p = 0.26). The plaque volume change (-15.9 +/- 22.2 vs. 4.0 +/- 14.0 mm(3), p = 0.01) and LAP volume change (-3.7 +/- 7.0 vs. 0.2 +/- 1.5 mm(3), p < 0.01) were significantly greater in the statin than the control group. The lumen volume (1.3 +/- 15.6 vs. -5.5 +/- 13.1 mm(3), p = 0.24) and remodeling index (-2.4 +/- 6.8% vs. -0.3 +/- 6.5%, p = 0.53) did not show the significant differences between the 2 groups. The decrease in the plaque volume was due to reduction in the LAP volume (R = 0.83, p < 0.01), and was not related to any changes in the lumen volume (R = 0.21, p = 0.24). CONCLUSIONS: This preliminary study suggests that serial CTA evaluation of coronary plaques allows for the assessment of interval change in the plaque morphology. Statin treatment results in decreases in the plaque and necrotic core volume. The features known to be associated with plaque instability.

The washout rate of (123)I-BMIPP and the evolution of left ventricular function in patients with successfully reperfused ST-segment elevation myocardial infarction: comparisons with the echocardiography.

The evolution of the oxidative metabolism of (11)C acetate parallels the recovery of left ventricular(LV) contraction following acute myocardial infarction(AMI). This study was designed to unravel, for the first time, the impact of the global washout rate(WR) of (123)I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) on the recovery of LV function followingAMI, as evidenced from conventional echocardiography.Twenty consecutive patients (age: 58 +/- 13 years; 16 males and 4 females) with ST-segment elevation myocardial infarction (STEMI) were enrolled and all of them underwent successful percutaneous coronary intervention (PCI). (123)I-BMIPP cardiac scintigraphy was performed at 7 +/- 3 days after admission. The WR was calculated from the polar map and the regional BMIPP defect score was calculated using a 17 segment model. Echocardiography was performed within 24 h of admission and at 3 months to record the ejection fraction (EF), the wall motion score index (WMSI), the ratio of the mitralinflow velocity to the early diastolic velocity (E/E0)and the myocardial performance index (MPI). The mean global WR of the BMIPP was 22.12 +/- 7.22%, and it was significantly correlated with the improvement of the WMSI (r = 0.61, P\0.004). However,the relative changes of the EF, E/E0 and MPI were not correlated with the WR. The BMIPP defect score (18 +/- 10) was significantly correlated with the WMSI on admission (r = 0.74, P = 0.0002), but the defect score was not correlated with the relative changes of any of the echocardiographic parameters. We proved that the WR of the BMIPP is a promising indicator of improvement of the LV wall motion (WMSI) following ST-segment elevation myocardial infarction and successful reperfusion.

Fatty acid metabolism and myocardial perfusion imaging for the evaluation of global left ventricular dysfunction following acute myocardial infarction: comparisons with echocardiography.

BACKGROUND: Myocardial fatty acid metabolic imaging with beta-methyl iodophenyl pentadecanoic acid (BMIPP) and perfusion imaging with tetrofosmin (TF) combined can predict post ischemic salvageable myocardium and persistent left ventricular (LV) dysfunction. This study was designed for the first time to assess systolic, diastolic and global LV dysfunction considering BMIPP and TF mismatched defect score (MMDS), and comparing this approach with the conventional Doppler echocardiography. METHODS: Thirty four patients with first acute myocardial infarction (AMI) were enrolled, and all of them underwent percutaneous coronary intervention (PCI). BMIPP and Tetrofosmin (TF) scans were performed at 7+/-3.5 days of admission. Echocardiography was performed within 24 h of admission, at an interval of 1 and 3 months. MMDS was compared with systolic: ejection fraction (EF), wall motion score index (WMSI), fractional shortening (FS); diastolic: mitral valve deceleration time (MVDT), E/E', left atrial volume index (LAVI); combined systolic and diastolic parameter: left ventricular myocardial performance index (LVMPI). RESULTS: A good correlation was observed between BMIPP and TF defect score (p<0.00001), and in 31 (91%) patients BMIPP defect score was higher than that of TF. The MMDS showed significant correlation with EF (r=-0.64, p=<0.00001), WMSI (r=0.61, p<0.0001), and FS(r=-0.65, p<0.00001), LAVI (r=-0.32, p<0.05), and LVMPI (r=0.37, p<0.02) during follow up echocardiography at 1 month. MVDT and E/E' did not correlate with MMDS. CONCLUSION: Perfusion-metabolism mismatched defect score was well correlated with the evolution of global left ventricular dysfunction following AMI evidenced from conventional Doppler echocardiography.

(123)I-BMIPP and (99m)Tc-TF discordance on myocardial scintigraphy and it's correlation with functional recovery following acute myocardial infarction: role of conventional echocardiography.

(123)I-beta-methyl-iodophenyl pentadecanoic acid (BMIPP) and (99m)Tc-Tetrofosmin (TF) mismatch designated as stunned myocardium having both systolic and diastolic components. The degree of mismatch might reflect subsequent functional improvement, and this study was designed to unravel the impact of mismatched defect score (MMDS) on recovery of both systolic and diastolic function following acute myocardial infarction (AMI). Forty patients with recent AMI were recruited, and all of them underwent emergency percutaneous coronary intervention. Echocardiography and BMIPP and TF cardiac scintigraphy were performed on 7 +/- 3 days of admission. Follow up echocardiography was performed after 3 months. MMDS were compared with the systolic [ejection fraction (EF) and wall motion score index (WMSI)] and diastolic [peak velocity of early diastolic filling of mitral inflow/peak early diastolic velocity of the mitral annulus(E/E') and left atrial volume index(LAVI)] parameters. BMIPP defect score was significantly higher than the TF defect score and there was a strong positive correlation between them (r = 0.90, P < 0.00001). Thirty-two (80%) patients showed mismatched defect and rest 8(20%) showed matched defect. Of 32 patients 24(75%), 22(69%), 19(59%), and 20(62.5%) showed improved EF, WMSI, E/E' and LAVI respectively. Conversely out of 8 only 2(25%), 1(12.5%), and 2(25%) patients showed improvement of EF, WMSI and LAVI, respectively. E/E' was not improved in patients with matched defect. MMDS were significantly correlated with the improvement of EF (r = -0.46, P = 0.002), WMSI (r = 0.41, P = 0.007), E/E' (r = 0.56, P < 0.0002), and LAVI (r = 0.44, P = 0.004). Mismatched defect score could predict the approximate amount of viable dysfunctional myocardium, and the degree of mismatch showed a significant correlation with the improvement of both systolic and diastolic function.

Computed tomographic angiography characteristics of atherosclerotic plaques subsequently resulting in acute coronary syndrome.

OBJECTIVES: In a computed tomographic (CT) angiography study, we identified the characteristics of atherosclerotic lesions that were associated with subsequent development of acute coronary syndrome (ACS). BACKGROUND: The CT characteristics of culprit lesions in ACS include positive vessel remodeling (PR) and low-attenuation plaques (LAP). These 2 features have been observed in the lesions that have already resulted in ACS, but their prospective relation to ACS has not been previously described. METHODS: In 1,059 patients who underwent CT angiography, atherosclerotic lesions were analyzed for the presence of 2 features: PR and LAP. The remodeling index, and plaque and LAP areas and volumes were calculated. The plaque characteristics of lesions resulting in ACS during the follow-up of 27 +/- 10 months were evaluated. RESULTS: Of the 45 patients showing plaques with both PR and LAP (2-feature positive plaques), ACS developed in 10 (22.2%), compared with 1 (3.7%) of the 27 patients with plaques displaying either feature (1-feature positive plaques). In only 4 (0.5%) of the 820 patients with neither PR nor LAP (2-feature negative plaques) did ACS develop. None of the 167 patients with normal angiograms had acute coronary events (p < 0.001). ACS was independently predicted by PR and/or LAP (hazard ratio: 22.8, 95% confidence interval: 6.9 to 75.2, p < 0.001). Among 2- or 1-feature positive segments, those resulting in ACS demonstrated significantly larger remodeling index (126.7 +/- 3.9% vs. 113.4 +/- 1.6%, p = 0.003), plaque volume (134.9 +/- 14.1 mm(3) vs. 57.8 +/- 5.7 mm(3), p < 0.001), LAP volume (20.4 +/- 3.4 mm(3) vs. 1.1 +/- 1.4 mm(3), p < 0.001), and percent LAP/total plaque area (21.4 +/- 3.7 mm(2) vs. 7.7 +/- 1.5 mm(2), p = 0.001) compared with segments not resulting in ACS. CONCLUSIONS: The patients demonstrating positively remodeled coronary segments with low-attenuation plaques on CT angiography were at a higher risk of ACS developing over time when compared with patients having lesions without these characteristics.

Multislice computed tomographic characteristics of coronary lesions in acute coronary syndromes.

OBJECTIVES: To evaluate the feasibility of noninvasive assessment of the characteristics of disrupted atherosclerotic plaques, the authors interrogated the culprit lesions in acute coronary syndromes (ACS) by multislice computed tomography (CT). BACKGROUND: Disrupted atherosclerotic plaques responsible for ACS histopathologically demonstrate large lipid cores and positive vascular remodeling. It is expected that plaques vulnerable to rupture should bear similar imaging signatures by CT. METHODS: Either 0.5-mm x 16-slice or 64-slice CT was performed in 38 patients with ACS and compared with 33 patients with stable angina pectoris (SAP) before percutaneous coronary intervention. The coronary plaques in ACS and SAP were evaluated for the CT plaque characteristics, including vessel remodeling, consistency of noncalcified plaque (NCP <30 HU or 30 HU

Applicability of ECG-gated multislice helical ct to patients with atrial fibrillation.

BACKGROUND: Multislice computed tomography coronary angiography (CTCA) is reconstructed by ECG gating and consequently it is difficult to obtain coronary artery images from patients with arrhythmias, such as atrial fibrillation (AF), by the conventional method. METHODS AND RESULTS: Eleven patients with AF (9 males, 2 females; mean age: 62.5 years) underwent CTCA using a slice thickness of 0.5 mm, gantry rotation of 0.4 or 0.5 s/rot and pitch of 3.2-4.0. A segmented reconstruction method was used to construct CTCA images at the conventional relative 70-75% (mid-diastolic phase) and 30-35% (end-systolic phase) of the R-R interval and furthermore, the absolute mid-diastolic phase and end-systolic phase from the R wave. Three investigators, who were unaware of the coronary angiography results, independently evaluated the curved multiplanar reconstruction (MPR) images. In both the relative and absolute phase reconstruction, there were motion artifacts in the mid-diastolic than in the end-systolic phase. The absolute phase images had less motion artifacts than the conventional relative phase images. Optimal curved MPR images were obtained in the absolute end-systolic phase. The quality and motion artifacts of those optimal images from AF patients were similar to those from patients in sinus rhythm. CONCLUSION: The absolute end-systolic phase is the best time to get optimal CTCA images in AF patients.